Rigid structure comprised of hollow,sealed spheres bonded together



W. C. GREGORY RIGID STRUCTURE COMPRISED OF HOLLOW 3,427,139 SEALED Feb.11, 1969 SPHERES BONDED TOGETHER l of 2 Sheet Filed June 7, 1967 llllMAM.

Feb. 11, 1969 w REGOR 3,427,139

RIGID STRUCTURE GOMPRISED 0F HOLLOW. SEALED SPHERES BONDED TOGETHERFiled June 7, 1967 'IIIIII/IJ L7 ve 1110; 38

United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE 'A rigidstructure comprised of abutting, hollow, sealed spheres bonded togetherinto a predetermined shape. The interiors of each of the spheres aremaintained at a pressure substantially different from atmosphericpressure at ground level. The structure is rigidified by a plurality ofsealed tubes disposed in spaces between the spheres and abut thesurrounding spheres to reinforce the structure.

This application is a continuation-in-part of pending US. patentapplication Ser. No. 474,118, filed July 22, 1965, now abandoned.

Brief summary of the invention The invention relates to pressurizedspheres which may be manufactured in steps, and the interiors thereof,durin the manufacture, are converted from a solid to a gas wherein thesphere will have an internal pressure different than atmosphericpressure at ground level. Further, while the individual pressurizedspheres are each capable of independent use, a plurality of the spheresmay be combined with hollow, pressurized tubular material to create arigid, reinforced structure which may be used as insulation, or may beused to suspend machinery.

An object of this invention is to provide hollow spheres adapted forindividual or multiple use wherein each of the spheres has a minimumwall thickness of metal and a maximum interior gas pressure.

Another object of this invention is to provide a rigid structurecomprising a plurality of substantially equal size, independentlysealed, hollow, rigid spheres having greater interior pressure than theexterior atmosphere, wherein said spheres are bonded together, and aplurality of hollow, pressurized tubes are disposed between said sphereswhereby the spheres and tubes may be bonded together to complete areinforced rigid structure.

Brief description of the drawings FIGURE 1 is a cross-sectional view ofa sphere at the initial stage of manufacture.

FIGURE 2 is a cross-sectional view of a heat treating pressure furnaceshowing a pair of spheres at the time of insertion into the furnace (A,left side of furnace), and a pair of spheres which have been treated inthe furnace (B, right side of furnace).

FIGURE 3 is a cross-sectionl view of a pressurized sphere wherein thesolid core has been converted to gas.

FIGURE 4 is a modified sphere at the initial stage f manufacture,covered with a bonding layer.

FIGURE 5 is a cross-sectional view of a pressurized sphere at thecompletion of manufacture, illustrating a vent projecting through thewall of the sphere.

FIGURE 6 is similar to FIGURE 5, except that the gas is being expelledthrough the vent.

FIGURE 7 is a cross-sectional view of a modified sphere illustrating adifferent type of interior gas than that illustrated in FIGURE 3.

FIGURE 8 illustrates a sphere similar to FIGURE 3.

FIGURE 9 is a crosssectional view illustrating a presire surized spherein combination with other spheres, and adapted to be used as a bulletshield.

FIGURES 10, 11 and 12 illustrate the steps in the manufacture of amodified vacuum sphere structure.

FIGURE 13 is a cross-sectional view illustrating a form of rigidstructure produced by a plurality of pressurized spheres.

FIGURE 14 illustrates a modified rigid structure utilizing the spheresas shown in FIGURE 13.

FIGURE 15 is a cross-sectional view of a novel pressurized tubularstructure suitable for binding and reinforcing pressurized spheres.

FIGURE 16 is a side view, partially in section, of the tube illustratedin FIGURE 15 FIGURE 17 is a cross-sectional view of a plurality ofpressurized spheres surrounding a plurality of pressurized tubes whereinthe tubes and spheres are bonded together to reinforce a rigidifiedstructure.

FIGURE 18 is a view of a rigid structure, partially in section,illustrating the pressurized spheres and pressurized tubes united.

FIGURE 19 is an end view of the structure identified in FIGURE 18.

Description of the preferred embodiments A single pressurized spherehaving a solid core 1 of a material which is capable of oxidizing itselfwhen heated is illustrated in FIGURE 1. This core may be mechanicallyformed, and may be of any desired shape, but preferably spherical. Thecore is preferably formed from nitrated cellulose, nitrated glycerine,collodion, or modified black gun powder. It has been found that blackgun powder, composed of carbon sulphur, and an oxidizing agent such aspotassium nitrate, is most effective. It should be noted that in orderto slow down any speed of oxidation, a plasticizer may be incorporatedwith the gun powder to achieve the desired effect.

The size of the sphere, which appears to be particularly advantageous inthe manufacture of rigid structures, i a sphere having a radius of about.45 cc.

The core 1 is then coated with a conductive material 2, such asgraphite, silver, or copper, which may be deposited chemically aroundthe core 1. After the conductive material 2 completely encases the core,a deposit of structural material 3, such as iron, chromium, nickel. ortheir alloys, is preferably electrolytically applied in a barrel platingmachine, not shown. Other methods, such as spraying and dipping, may beutilized to achieve a complete coating of the core 1 and conductivematerial 2.

After a sphere, such as illustrated in FIGURE 1, has been formed, it isthen placed within a heat treating pressure furnace, such asschematically illustrated in FIG- URE 2, and by controlled heating,heated to approximately F. The controlled intensified heating of thesphere will convert the core material 1 into a gas, such as isillustrated by the numeral 7 in FIGURE 3. With the core preferably ofabout .45 cc. radius, the gas 7 which is created from the black gunpowder, will equal about 600 atmospheres, or a pressure of about 9000p.s.i. at 0 C.

When oxidation occurs of the black gun powder core 1, about 700 caloriesof black gun powder is liberated. Such amount of heat will generallyweaken the structural metal 3. To overcome the weakening of thestructural material 3, it is preferred that the heated sphere, such asshown in the right-hand side of the furnace in FIG- U-RE 2, be placed ina pressure furnace, not illustrated.

The sphere is then encased in an alloy 4, such as mercury, Woodsmaterial, lead, silver solder, or the like, so that as the metal in thepressure furnace, illustrated, expands, it will increase in volume,thereby applying pressure to and increasing the entire pressurizedsphere.

The sphere illustrated in FIGURE 4 is similar to that illustrated inFIGURE 1, with the exception that after the structural material 10 hasbeen formed on the sphere, a deposit of binder metal having a lowermelting polut than the structural material 10, such as brass or bronze,is deposited therearound. This binder metal may be applied by spraying,or by chemical precipitation.

The illustrations in FIGURES 5 and 6 show a sphere similar to the spherein FIGURE 3, which has been pressurized, but there is added thereto arelatively small orifice 13 extending from the interior of the spherethrough a wall to the exterior. The gas 12 in FIGURES 5 and 6 ispreferably a highly compressed smoke which can be produced from a coreof black powder with a sufficient excess of powdered charcoal that onlypart of it is oxidized. upon combustion. The particular structureillustrated in FIGURES 5 and 6 is adapted for use as a tracer wherebywhen the sphere is struck with a blow, the plastic cap 14 will bedisengaged from over the orifice 13, allowing the smoke 12 to beexpelled in a trail 15, such as is seen in FIGURE 6.

It should be realized that any type of chemical may be added to the core1, which will produce a colorable gas or vapor 12, such as illustratedin FIGURE 7. In the case of the sphere of FIGURE 7, the exterior coatingis made relatively thin, so that on impact it will burst, expelling thecolored gas 12.

The sphere illustrated in FIGURE 8 is depicted to represent a sphere tobe used as a ball bearing. When such is desired, the coating ispreferably of hard chrome. Such a structure as illustrated in FIGURE 8will produce a strong, lightweight ball bearing.

FIGURES 10 through 14 illustrate a modified embodiment of thepressurized sphere structures in the form of vacuum spheres. In thisembodiment, vacuum spheres are prepared by blowing thin walled glassspheres, by any suitable means. The core 21 is then encased within alayer of material, such as magnesium or a magnesium alloy depositedthereon. The deposit of such material is preferably formed by sprayingmagnesium powder onto the outer surface of the glass sphere 21.

After the layer 22 is deposited on the sphere, structural metal 24, ofthe type previously described, is then applied to the sphere. After thespheres have the structural metal applied, it is preferred that they beplaced in a plating barrel containing a zinc cyanide bath, includingzinc oxide, sodium cyanide, and sodium hydroxide, and heated to atemperature of between 100 to 125 F. The zinc coated spheres are thenrinsed and dried.

The structure as illustrated in FIGURE 10 is then placed in a furnacesuch as schematically illustrated in FIGURE 11, where, upon heating, theglass spheres 21 will break, exposing the air, whereby the nitrogen andoxygen combine with the magnesium or magnesium alloy, so that thereaction of the nitrogen and oxygen with the magnesium produces a vacuum23.

FIGURES l5 and 16 illustrate a tubular structure suitable for binding asphere such as illustrated in FIG- URES 1 and 10, into a rigidstructure. The ducts or tubes are made of layers of material ashereinafter described, which decompose and melt at predeterminedtemperatures in a pressure heat furnace, so as to form hollow structureswhich are bound together in the position in which they are formed. Thisbinder and hollow tube structure consists of a core 31, similar to thecore 1 of FIGURES 1 through 4. The core 31 is preferably covered with afabric 32 of asbestos. The fabric 32 is then encased in a layer of metal33. The outer surface of the metal layer 33 is a surface to which solderor other metal may be applied to bond the tube to the spheres.

The fabric 32 is preferably such that it will burn slowly, yet retainits original shape until the binding material 33 has cooled and chilledto a solid state before the organic fabric has burned and fallen apart.

Once the tubular structures illustrated in FIGURES 1 5 and 1 6 areprepared and pressurized, they may then be placed amongst a plurality ofpressurized spheres illustrated in FIGURE 3, or vacuum spheresillustrated in FIGURE 12. In order to bind the various spheres and tubestogether, it is desired that a binding metal, such as solder, not shown,be applied, so that as the spheres and tubes are heated, the resultantstructure, as illustrated in FIGURES 18 and 19, will be accomplished,whereby the spheres and tubes are fused together.

In FIGURE 18 there is schematically illustrated a pressure furnaceincluding sides 37 and top andbot-tom 39 of the furnace, which arepreferably movable so that the spheres and tubes within the furnacewhich are being heated may expand outwardly against the end or bottom 39because of the changing volume created by heat treating. On therighthand side of FIGURE 18, represented by the letter B, the completedstructure is illustrated in its fused, finished, rigidified form.

A structure such as illustrated in FIGURE 17, formed into desired shapesand sizes, creates eflicient heat bar riers and/or encasement formachinery parts.

It can be seen that the tubes illustrated in FIGURE 15 are sealed, sothat the pressure can be maintained in the core area.

Although I have herein shown and described my invention in what I haveconceived to be the most practical and preferred embodiments, it isrecognized that departures may be made therefrom within the scope of myinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent structures and devices.

I claim:

1. A rigid structure comprising a plurality of substantially equal size,independently sealed, hollow, rigid spheres having an interior pressuresubstantially different from atmospheric pressure at ground level, saidspheres being maintained together in a predetermined rigid shape andcompacted to abut one another, a plurality of independently sealed,substantially parallel, hollow tubes, said tubes being diametricallydisposed between said spheres, and being of sufiicient external diameterwhen positioned in the spaces between said spheres to abut each of thesurrounding spheres, and a rigid bonding mass of filler material whichfills the interstices between said spheres and said tubes to bind themtogether and rigidity the structure.

2. A rigid structure as defined in claim 1, wherein the interiorpressure of the spheres is greater than ground level atmosphericpressure.

3. A rigid structure as defined in claim 1, wherein the interiorpressure of the spheres is less than ground level atmospheric pressure.

References Cited RICHARD O. DEAN, Primary Examiner.

US. Cl. X.R.

